Reviewed-by: Tomas Mraz <tomas@openssl.org> (Merged from https://github.com/openssl/openssl/pull/13719)
Previously, it was sufficient to have certSign in keyUsage when the basicConstraints extension was missing. That is still accepted in a trust anchor, but is no longer accepted in an intermediate CA. Reviewed-by: Rich Salz <rsalz@openssl.org>